01 August 2014

Fireflies

Welcome back. Jogging a few weeks ago, I collided with a firefly. Neither of us was going very fast. I never do. Although the firefly settled in on my reflective vest and seemed content, flashing regularly, I decided after a few minutes of continued jogging that we’d better go our separate ways.

“Can you find your way home?” I asked, having no idea if fireflies have homes.

Not the firefly I collided with but one seen on multiple websites.

Flash…flash…flash, it responded without budging. “Oh, come on. Think about it,” I tried to reason. “What kind of life can you have on my vest?” Flash…flash…flash. Would it be homesick I wondered. “I’ve taken you far from everything you ever knew.” Flash…flash…flash. “Enough,” I said in guilt-ridden frustration. “I’m sorry, but you’ll have to go.” I gently shook it loose and watched until the flashing disappeared in the darkness.

The collision wasn’t an isolated incident. There were also fireflies last year, my first year here in Wisconsin. Then, too, I saw them for only a few weeks in late spring or early summer when I passed about 3:45 AM every non-rainy morning. Though I might see an isolated flash anywhere along my mile-plus route, there was always a concentration of fireflies at and near the same road intersection.

Fireflies are prevalent at predawn alongthe roadside at and near this corner, butfew are seen on the other side of theroad or elsewhere on my jogging route.

If these fireflies were just stragglers after a wild night of partying and hooking up, it must have been quite a scene hours earlier.

The collision made me realize how little I knew about fireflies, despite having showcased two I’d captured in a glass jar, after nailing holes in the metal lid, when I was about 9 years old. I decided then and there that fireflies would be my next blog topic. Here is some of what I found.

Firefly Findings

Fireflies, or if you prefer, lightning bugs, are winged beetles of the family Lampyridae. There are about 2,000 species, not all of which flash. Those we know best are nocturnal. Fireflies are found in temperate and tropical regions, generally in more humid environments. The grass strip at the road intersection of my encounters is a wetter area between the farmed field and the raised roadbed. It also follows a shallow drainage ditch of sorts.

The firefly’s periodic flash is the quintessence of bioluminescence. (Do you remember my post on Puerto Rico’s bioluminescent bays, Time for a Bioluminescent Bay?) In short, the bioluminescent flash is an extremely efficient chemical reaction in which the enzyme luciferase acts on a substance, luciferin, in the presence of just the right stuff--magnesium ions, ATP, and oxygen--to produce light with virtually no heat. A firefly’s bioluminescence begins when it’s an egg and ends with its demise.

When I was writing insect verse in college (Praying Mantis Photo Addendum), I latched onto the tidbit that male fireflies flash a species-specific pattern to advertise for females. The females flash back if they’re interested. That still seems to be one accepted reason for flashing, and I still think it’s worthy of verse.

Anyway, shortly after mating, the female lays her fertilized eggs on or below the ground surface. Larvae hatch a few weeks later; feed on worms, slugs or snails until the summer’s end; hibernate over the winter and then emerge in spring. After several weeks of feeding and pupating, the fireflies come forth as adults, which may feed on nectar or pollen or not at all. Who has time to dine? They live only long enough to mate and lay eggs.

Wrap Up

As you’d expect, what’s known about fireflies varies with species and there’s lots to learn--like how groups of certain fireflies synchronize their flashes. But I’ve filled in enough blanks for me, at least until I meet up with those emerging adult fireflies again next year. When I do, I now know it’s estimated they can fly up to about 20 mph.

Almost forgot…one item of importance. Fireflies are the good guys, and it appears they’re on the decline. Do whatever you can to support them. Thanks for stopping by.